Mine now is running 47mph (DGPS) with just me and a 1/4 tank of fuel. Loaded fish ready with 4 guys I am running on average WOT 44mph. Currently swinging a 17p Yam SWS prop. on my OX66 250hp.
When my 250 Yam was brand new (just after break-in
with no t-top and about 5gal of fuel) I hit 53mph (GPS) swinging a 19p stiletto. I had the tabs full up and was running in a river trimmed to the max and the ole SeaCraft felt like she was chine walking...
The 19p was pretty good with a light load but I could not get up into the recommended RPM range with a load swinging that prop.
FWIW - According to my floscan at WOT I am burning between 27 and 29gph.. so I do this VERY infrequently now days..